The sea surface temperature deviation and the heat flow at the sea-air interface

The deviation of the sea surface temperature from the water temperature below is calculated as a function of the heat flow through the air-sea interface, using wind tunnel determinations of the effective thermal diffusivity in a boundary layer. The influence ofQ, shortwave radiation, andH, latent and sensible heat transfer plus effective back radiation, and U, wind speed, can be described by:T ₀ –T _w =C ₁ ·H/U +C ₂ ·Q/U. The calculated coefficients vary slightly with reference depth, Tables II and III. They are in good agreement with independent observations.On leave at Department of Oceanography, Oregon State University, Corvallis, Oregon in 1969–70.     

Late Quaternary ice-rich permafrost sequences as a paleoenvironmental archive for the Laptev Sea Region in northern Siberia

Ice-rich permafrost sequences with large polygonal ice wedges represent excellent archives for paleoenvironmental reconstruction. Such deposits contain numerous well-preserved records (ground ice, paleosols, peat beds, different types of fossils), which permit characterization of environmental conditions during a clearly defined period of the past 60 ka. Based on field investigations carried out within framework of the German-Russian project "Laptev Sea System 2000" on the Bykovsky Peninsula (SE of the Lena Delta) results from cryolithological studies, sedimentological analyses, as well as new radiocarbon data are presented. For the first time it is shown that the Ice Complex accumulated without significant interruptions from approximately 60 k.y. B.P. until the end of the Pleistocene. Geochemical data (total organic carbon, C/N, '¹³C_org) and the mass-specific magnetic susceptibility clearly show changing environmental conditions from stadial to interstadial times in the Late Pleistocene and during the transition to the Holocene. These results permit us to reconstruct the development of an Arctic periglacial landscape in the coastal lowland during Ice Complex formation in the Late Quaternary. This evolution coincided generally with the global environmental trend up to marine isotope stage 4.     

Secondary Ca–Al silicates in plutonic rocks: implications for their cooling history

Secondary Ca-Al silicates are used to constrain the P-T-x conditions of the very early post-magmatic stage of the intermediate to basic Hercynian plutonic complexes of Charroux-Civray (NW Massif Central, France) and Fichtelgebirge (NE Bavaria, Germany). The secondary Ca-Al silicates hydrogarnet, prehnite, pumpellyite, epidote and laumontite form lenses within unaltered or only slightly chloritized biotite. Hydrogarnet as the first occurring Ca-Al silicate phase crystallizes at temperatures above 340 °C. The common paragenesis prehnite + pumpellyite post-dates hydrogarnet and indicates rather narrow ranges of temperature (200-280 °C) and pressure (2-3 kbar). Laumontite is formed at the end of Ca-Al silicate crystallization (180-260 °C, 1-3 kbar), mostly in small fractures in association with prehnite and adularia. The observed crystallization sequence of the Ca-Al silicates and their stabilities define a retrograde alteration path for the plutonic rocks. The Ca-Al silicate assemblage results from an early pervasive alteration of the plutonic rocks by low X_CO2 fluids during post-magmatic cooling. Subsolidus cooling starts at about 4 kbar at solidus temperatures as indicated by magmatic epidote stability, hornblende barometry and fluid inclusion data, and continues under slightly decreasing pressure (uplift) down to 2-3 kbar at 200-280 °C (prehnite-pumpellyite paragenesis). This shows that Ca-Al silicate assemblages may be a unique tool to constrain the P-T conditions of the subsolidus cooling of intermediate to basic plutonic bodies.     

Chalcides and pnictides of group VIII transition metals: Far-infrared spectroscopic studies on compounds MX 2, MXY,and MY 2 with pyrite,marcasite, and arsenopyrite structure

The far-infrared (FIR) spectra of pyrites, marcasites and loellingites, and arsenopyrites of the type MX ₂, MY ₂, and MXY with M=Fe, Co, Ru, Rh, Os, Ir X=S, Se, Te, and Y=P, As, and Sb have been studied, including group theoretical treatment of the phonon modes. The internal Y - Y and X - Y stretching modes, infrared (IR) allowed only in the case of the arsenopyrites, have been found to be in the range 440–490, 470–510, 450–490, 430–450 and 400–420 cm^?1 for MP ₂, MPS, MPSe, MAsS, and MSbS type compounds, respectively. From the obtained spectra intensity weighted mean phonon frequencies, i.e. central frequencies as defined by Plendl (1961), and mass weighted ones have been calculated and interpreted in terms of the strength of the MX and MY bonds, especially comparing 3d, 4d, and 5d transition metal compounds. Method of preparation and X-ray data of the chalcides and pnictides studied are also given.     

Looking for a needle in a haystack: Probability density based classification and reconstruction of dormers from 3D point clouds

Accurate reconstruction of roofs with dormers is challenging. Without careful separation of the dormer points from the points on the roof surface, the estimation of the roof areas is distorted. The characteristic distortion of the density distribution in comparison to the expected normal distribution is the starting point of our method. We propose a hierarchical method which improves roof reconstruction from LiDAR point clouds in a model‐based manner, separating dormer points from roof points using classification methods. The key idea is to exploit probability density functions to reveal roof properties and to skilfully design the features for a supervised learning method using support vector machines. The approach is tested based on real data as well as simulated point clouds.     

Climate change impacts on runoff in the Ferghana Valley (Central Asia)

The main freshwater source of arid/semi-arid Central Asia is stored in its high mountain glaciers. Water for the downstream countries is mainly supplied through the Syrdarya River that originates at the confluence of the Naryn and Karadarya rivers in the Ferghana Valley. Runoff generation from glaciers plays a crucial role, although a considerable number of small tributaries supply the river with additional runoff from snowmelt and rain in the mountains surrounding the Ferghana Valley. Observations of rising air temperature and accelerated glacier shrinkage make it most likely that the relative contributions of the smaller tributaries will increase. Hitherto, assessments of climate change effects on the water resource availability have largely neglected the growing importance of the runoff from smaller tributaries. We used a dynamically downscaled A1B SRES scenario for climate change effects for the period 2071–2100 in relation to the reference period of 1971–2000 and a version of the conceptual hydrological Hydrologiska Byråns Vattenavdelning model (HBV-light) to estimate runoff contributions with particular respect to the small tributaries. The simulations showed a 12–42% decrease in summer runoff; and a 44–107% increase in winter-spring runoff. This indicates the hydrological regime is shifting towards a runoff from snowmelt earlier in the year. The study suggests that actions for climate change adaptation should be complemented by land management configured to secure optimal runoff supplement from the smaller catchments.     

Time-frequency analysis based on curvelet transforms with time skewing

Oil and gas exploration gradually changes to the deep and complex areas. The quality of seismic data restricts the effective application of conventional time-frequency analysis technology, especially in the case of low signal-to-noise ratio. To address this problem, we propose a curvelet-based time-frequency analysis method, which is suitable for seismic data, and takes into account the lateral variation of seismic data. We first construct a kind of curvelet adapted to seismic data. By adjusting the rotation mode of the curvelet in the form of time skewing, the scale parameter can be directly related to the frequency of the seismic data. Therefore, the curvelet coefficients at different scales can reflect the time-frequency information of the seismic data. Then, the curvelet coefficients, which represent the dominant azimuthal pattern, are converted to the time-frequency domain. Since the curvelet transform is a kind of sparse representation for the signal, the screening process of the dominant coefficient masks most of the random noise, which enables the method to adapt for the low signal-to-noise ratio data. Results of synthetic and field data experiments using the proposed method demonstrate that it is a good approach to identify weak signals from strong noise in the time-frequency domain.